From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Glauber Costa <glommer@parallels.com>
Cc: linux-kernel@vger.kernel.org, xemul@parallels.com,
paul@paulmenage.org, lizf@cn.fujitsu.com, daniel.lezcano@free.fr,
mingo@elte.hu, jbottomley@parallels.com
Subject: Re: [PATCH 0/9] Per-cgroup /proc/stat
Date: Wed, 14 Sep 2011 22:13:16 +0200 [thread overview]
Message-ID: <1316031196.5040.46.camel@twins> (raw)
In-Reply-To: <1316030695-19826-1-git-send-email-glommer@parallels.com>
On Wed, 2011-09-14 at 17:04 -0300, Glauber Costa wrote:
> [[ For those getting this twice: I sent it previously to containers
> ml, but I guess it was out. Sending now to a broader audience anyway ]]
>
> Hi,
>
> This patchset is a simple initial proposal for a per-cgroup/container
> display of /proc/stat. The display method is based on Daniel's idea of
> exposing a file that can be bind mounted (Daniel, is that more or less
> what you had in mind?)
>
> To grab the stats themselves, I am (ab)using cpuacct cgroup. percpu counters
> are dropped in favor of normal percpu pointers, so we can easily track
> per-cpu quantities.
>
> In case you guys like this idea, my TODO list would include the removal
> of the show stat code in fs/proc/stat.c altogether, and the displaying
> of some fields I haven't touched yet.
>
> Also, to demonstrate one of the potential ideas for such method, I
> implemented a feature comonly found in hypervisors - steal time - on top
> of it. I arguee that containers can/should also display steal time when
> available. Turns out that due to the fact that we run on the same kernel,
> steal time is quite easy to implement once we have per-container tick
> accounting in place.
>
> Please let me know what you guys think
>
> Glauber Costa (9):
> Remove parent field in cpuacct cgroup
> Make cpuacct fields per cpu variables
> Include nice values in cpuacct
> Include irq and softirq fields in cpuacct
> Include guest fields in cpuacct
> Include idle and iowait fields in cpuacct
> Create cpuacct.proc.stat file
> per-cgroup boot time
> Report steal time for cgroup
>
> kernel/sched.c | 265 +++++++++++++++++++++++++++++++++++++++++++++++++-------
> 1 files changed, 234 insertions(+), 31 deletions(-)
I hate it already.. it just smells of more senseless accounting
overhead.
Guys we should seriously trim back a lot of that code, not grow ever
more and more. The sad fact is that if you build a kernel with
cpu-cgroup support the context switch cost is more than double that of a
kernel without, and then you haven't even started creating cgroups yet.
Also, how doesn't all this duplicate part of cpuacct-cgroup?
/me won't actually look at the patches for a little while longer.
next prev parent reply other threads:[~2011-09-14 20:13 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-14 20:04 [PATCH 0/9] Per-cgroup /proc/stat Glauber Costa
2011-09-14 20:04 ` [PATCH 1/9] Remove parent field in cpuacct cgroup Glauber Costa
2011-09-19 16:03 ` Peter Zijlstra
2011-09-19 16:09 ` Glauber Costa
2011-09-19 16:19 ` Peter Zijlstra
2011-09-19 16:30 ` Glauber Costa
2011-09-19 16:39 ` Peter Zijlstra
2011-09-19 16:41 ` Glauber Costa
2011-09-19 18:40 ` Peter Zijlstra
2011-09-20 17:29 ` Srivatsa Vaddagiri
2011-09-22 15:11 ` Balbir Singh
2011-09-22 15:17 ` Peter Zijlstra
2011-09-23 8:09 ` Balbir Singh
2011-09-23 14:35 ` Peter Zijlstra
2011-09-23 15:45 ` Glauber Costa
2011-09-19 18:35 ` Peter Zijlstra
2011-09-19 18:38 ` Glauber Costa
2011-09-19 18:44 ` Peter Zijlstra
2011-09-19 19:14 ` Glauber Costa
2011-09-19 19:18 ` Peter Zijlstra
2011-09-19 19:19 ` Glauber Costa
2011-09-14 20:04 ` [PATCH 2/9] Make cpuacct fields per cpu variables Glauber Costa
2011-09-19 16:10 ` Peter Zijlstra
2011-09-14 20:04 ` [PATCH 3/9] Include nice values in cpuacct Glauber Costa
2011-09-19 16:19 ` Peter Zijlstra
2011-09-19 16:26 ` Glauber Costa
2011-09-19 18:36 ` Peter Zijlstra
2011-09-19 18:37 ` Glauber Costa
2011-09-14 20:04 ` [PATCH 4/9] Include irq and softirq fields " Glauber Costa
2011-09-19 18:38 ` Peter Zijlstra
2011-09-19 18:40 ` Glauber Costa
2011-09-14 20:04 ` [PATCH 5/9] Include guest " Glauber Costa
2011-09-14 20:04 ` [PATCH 6/9] Include idle and iowait " Glauber Costa
2011-09-20 9:21 ` Peter Zijlstra
2011-09-20 12:36 ` Glauber Costa
2011-09-20 12:58 ` Peter Zijlstra
2011-09-20 12:58 ` Glauber Costa
2011-09-20 13:05 ` Peter Zijlstra
2011-09-20 13:29 ` Glauber Costa
2011-09-14 20:04 ` [PATCH 7/9] Create cpuacct.proc.stat file Glauber Costa
2011-09-20 9:22 ` Peter Zijlstra
2011-09-20 12:22 ` Glauber Costa
2011-09-14 20:04 ` [PATCH 8/9] per-cgroup boot time Glauber Costa
2011-09-20 9:25 ` Peter Zijlstra
2011-09-20 12:37 ` Glauber Costa
2011-09-20 13:04 ` Peter Zijlstra
2011-09-20 13:06 ` Glauber Costa
2011-09-20 13:31 ` Peter Zijlstra
2011-09-14 20:04 ` [PATCH 9/9] Report steal time for cgroup Glauber Costa
2011-09-20 9:29 ` Peter Zijlstra
2011-09-14 20:13 ` Peter Zijlstra [this message]
2011-09-14 20:20 ` [PATCH 0/9] Per-cgroup /proc/stat Glauber Costa
2011-09-15 8:53 ` Peter Zijlstra
2011-09-14 20:23 ` Andi Kleen
2011-09-15 8:56 ` Peter Zijlstra
2011-09-19 23:07 ` Paul Turner
2011-09-20 8:33 ` Peter Zijlstra
2011-09-20 21:37 ` Glauber Costa
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